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Edyta Janik Marcin Niemcewicz Marcin Podogrocki Michal Ceremuga Leslaw Gorniak Maksymilian Stela Michal Bijak 《Molecules (Basel, Switzerland)》2021,26(13)
Mycotoxins represent a wide range of secondary, naturally occurring and practically unavoidable fungal metabolites. They contaminate various agricultural commodities like cereals, maize, peanuts, fruits, and feed at any stage in pre- or post-harvest conditions. Consumption of mycotoxin-contaminated food and feed can cause acute or chronic toxicity in human and animals. The risk that is posed to public health have prompted the need to develop methods of analysis and detection of mycotoxins in food products. Mycotoxins wide range of structural diversity, high chemical stability, and low concentrations in tested samples require robust, effective, and comprehensible detection methods. This review summarizes current methods, such as chromatographic and immunochemical techniques, as well as novel, alternative approaches like biosensors, electronic noses, or molecularly imprinted polymers that have been successfully applied in detection and identification of various mycotoxins in food commodities. In order to highlight the significance of sampling and sample treatment in the analytical process, these steps have been comprehensively described. 相似文献
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Emil Pop Stanislaw Rachwal Marcus E. Brewster 《International journal of quantum chemistry》1996,60(8):1829-1834
The allylic rearrangement of trans-pinocarveol esters ( I ) to myrtenol esters ( II ), a reaction of interest in the chemistry of terpenes and cannabinoids, has been theoretically investigated. The intramolecular, cyclization-induced rearrangement results in equilibrium mixtures of the starting compounds and the products with the ratio of I vs. II in the equilibrium mixture being determined by their thermodynamic stabilities. The relative thermodynamic stabilities as reflected by calculated AM1 heats of formations (ΔHf) were determined for various I-II ester pairs. The study, in agreement with available experimental evidence, indicates that generally I , which contain an endocyclic double bond, are more stable and thus predominantly form following rearrangements. In two cases (acetate and pivalate) the stability is reversed. Calculations performed for similar structures, esters of 2-methylene cyclohexane-1-ol ( IV ) and 1-cyclohexene-1-methanol ( V ) gave similar results. Structural and electronic factors which might influence the stability of these compounds were examined. Interestingly, a correlation between thermodynamic stability and dipole moments was observed. © 1996 John Wiley & Sons, Inc. 相似文献
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Alan R. Katritzky Stanislaw Rachwal Bogumila Rachwal John W. Frankenfeld 《国际化学动力学杂志》1995,27(4):351-357
The 1H NMR technique was applied for the measurement of the isomerization rates of N-ethyl-N-[(benzotriazol-1-yl)methyl]aniline ( 4 ) and 4-butyl-N-[(benzotriazol-1-yl)methyl]aniline ( 7 ) to the corresponding benzotriazol-2-yl isomers in dioxane-d8 at 35°C. The rate constants obtained for pure dioxane-d8 were 1.62 and 0.28 h?1 for 4 and 7 , respectively. For both compounds, addition to acetic acid to the dioxane solutions accelerated the isomerizations whereas addition of triethylamine retarded it strongly. Addition of water slowed the isomerization of 4 but accelerated that of 7 : the different effects operating in the two cases are discussed and rationalized. © 1995 John Wiley & Sons, Inc. 相似文献
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Reaction of N,N-bis[(benzotriazol-1-yl)methyl]aniline (2) with 1-vinylpyrrolidin-2-one gives a mixture of diastereomeric 1,7-bis(2-oxopyrrolidin-1-yl)julolidines 3. After reduction of 3 with LAH, the predominant trans diastereomer of 1,7-di(pyrrolidin-1-yl)julolidine (4) is separated. Reaction of 2 with ethyl vinyl ether yields predominantly trans-1,7-di(benzotriazol-1-yl)julolidine (11). Stepwise synthesis from tetrahydroquinoline 15 gives access to julolidines with two different substituents on C-1 and C-7. Reaction of 1-[(benzotriazol-1-yl)methyl]-1,2,3,4-tetrahydroquinoline (25) with enolizable aldehydes gives a mixture of tetrahydroquinolines 26-29 which are converted into single julolidine products upon treatment with sodium hydride, LAH, or phenylmagnesium bromide. Reactions of 1,2,3,4-tetrahydroquinolines with benzotriazole and 2 molar equiv of enolizable aldehydes gives 1,2,3-trisubstituted julolidines 38-41, which with lithium aluminum hydride, sodium hydride, or a Grignard reagent produce single diastereomers of products 42, 43, and 45, respectively. 相似文献
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Alan R. Katritzky Barbara Galuszka Stanislaw Rachwal Michael Black 《Journal of heterocyclic chemistry》1994,31(4):917-923
Boron trifluoride catalyses reactions of 1-(hydroxymethyl)benzotriazole with ketones to give predominantly monosubstituted Mannich products. In unsymmetrical ketones, a methylene is slightly more reactive than a methyl group. For 1,3-diketones and diethyl malonate, substitution occurs on the central methylene group. β-Aminocrotononitrile and β-aminocrotonate undergo Mannich condensations with benzotri-azole and formaldehyde without any catalyst. Preliminary investigations of the reactivity of the Mannich bases thus obtained are reported. 相似文献
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Alan R. Katritzky Stanislaw Rachwal Richard Ollmann 《Journal of heterocyclic chemistry》1994,31(4):775-779
The use of intermediate benzotriazol-l-yl derivatives simplified the procedures for the preparation of 5-methoxy-l-methylbenzimidazole and 6-methoxy-l-methylbenzimidazole starting from 4-methoxy-2-nitro-aniline. This strategy represents a novel and potentially general method for synthesis of 5- and 6-substituted-l-methylbenzimidazoles from 4-substituted anilines. Preparation of l-methyl-5-nitrobenzimidazole by reaction of 2-chloro-5-nitroaniline with methylamine and condensation of the obtained diamine with formic acid represents a special case. 相似文献
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Alan R. Katritzky Stanislaw Rachwal Terrance P. Smith Peter J. Steel 《Journal of heterocyclic chemistry》1995,32(3):979-984
2,6-Dihydroxy-4-methyl-3-pyridinecarbonitrile is converted via its 2,6-dichloro analog into the corresponding 2-amino-6-chloro, 2-chloro-6-amino, and 2,6-diamino derivatives. The last reacts with benzene-sulfonyl chloride to yield a tris-sulfonyl derivative, the structure of which is demonstrated by X-ray analysis. 相似文献